Predetermined bend line



Nov. 19, 1940. P. zALKlND PREDETERMINED BEND LINE Filed Oct. 19, 1935 2Sheets-Sheet 1 lNyENToR 9D/21190 ,aikzlzd BY MNH P. zALKlND 2,221,854

PREDETERMINED BEND LINE Filed Oct. 19, 1935 2 Sheets-Sheet 2 ATTORNEYPatented Nov. 19, 1940 UNITED sTATEs PATENT OFFICE vPREDETERi'iZINEmlSBENn-Lmr: i

Application October 19, 1935, Serial No. 45,710 9 Claims, 01. 13s- 34)My invention relates to novel structural mem-f bers, and moreparticularly, relates tq metallic members having incorporated therein aline of weakness which serves as a predetermined line on which themember may be manually bent.

My invention is particularly applicable in connection with sheetmaterial such as corrugated board, chip board, wood ply board, andsimilar materials; and in connection with such sheet material may beused for connecting such sheet material, or it may be used asreinforcement for such sheet material, or it may be used in a combinedconnecting and reinforcing member. However, I do not limit my inventionto use in connection with fibrous sheet material, as it may be'used in ametallic sheetforming the bending line therein.

In Serial Number 693,841 filed October 16, 1933 of which the applicationis a continuation in part, there is shown a collapsible casing anddrawer to which my invention is applied in several modiflcations.

I have discovered that by a no-vel'fabrication i of metal, I can bend italong predetermined lines, such fabricated metal thereafter having avariety of uses. Among other uses, such members may be used to securetwo parts to each other; to' reinforce casing edges; etc. In the lattercase, the members are permanently secured to the edges of the casingsand ,are bent over the casing edge along predetermined lines to form areinforcing member.

As above mentioned, I have shown such uses in Serial Number 693,841 inrelation to casings and drawers. Applications of my invention are shownin relation to cabinets in Serial Number 739,962 filed August 15, 1932.Also further applications in connection with casings and drawers areshown in my applications led coincidentally with this application andentitled: Roller casing, Serial No. 45,715; Three sided casing, SerialNo. 45,714; Panels, Serial No. 45,708; Container fastening means, SerialNo. 46,316; End fold casing, Serial No. 45.713; and Clips, Serial No.45,712.

Further uses of my invention may be in connection with decorativetables, hampers, ice cream shipping containers, etc. constructedprimarily of fibrous sheet material; or with decorative screens,

wall panels, column casings, or similar applications of sheet material,either entirely metallic,-fir partly metallic and partly fibrous.

Accordingly, objects of my invention are to provide a novel fabricatedmetal; a novel method of and means for bending metal along predeterminedlines; a metal in which a differential -if fiexure is produced along aline for predetermining the shape of the metal; a metal weakened along aline for predetermining the bend of the metal there along; a metalmember fabricated as for reinforcing casings; metal of the typedescribed above for securing members to each other; a reinforcing memberfor casings which is permanently secured to the casings and which doesnot prevent collapse of the casing for shipment; a metal member adaptedto secure the free edges of a casing for forming performing and securingadjacent sides of a oontainer.

In some instances it isdesirable'to reinforce the grid line. I havefound that this may be done with an additional strip of metal which mayeither be lighter or heavier than the metal of the grid. At the sametime, I have discovered that I may provide reinforcing of the bend linein several modifications and thereby obtain a smooth, unpierced surfaceover the line of bend without departing from the utility of myinvention. In certain of these modications the formation of the line ofbend itself serves as means for retaining the covering Iin positionedrelationship to the bend lines'.

Such instances as are indicated above may include adaptations such asthose where the grid is used to connect panels of a casing or cabinetwhere imperviousness is a desirable feature. f Such imperviousness maybe secured with my modified grid as the additional metal strip willcover the perforation made in the grid to determine -the bend line. Animpervious joint is particularly obtained with one form of my inventionwhich is described in greater detail later and in which a thin metalsheet is clinched over the bending strip with a layer of fibrousmaterial interposed therebetween. These three layers thus formed may besubstantially continuously adhesively united with each other whereby thegrid perforations become effectively sealed.

Another application of my covered grid lies in instances Where arelatively heavy compressive load is to be sustained. In such instanceit may be that if the grid were made suiiiciently heavy to sustain suchload, it would not readily be manually bendable. The'reinforcing appliedto the grid will provide compressure strength to the grid member withoutdetracting from the manual bendability if the proper form of my modifiedgrid is used.

Further applications of my covered grid lies in instances where the gridis to be passed through a lithographing press before it is applied tothe structure. It is diiilcult in the standard lithographing press .toutilize material of #24 gauge or heavier, with my covered grid, itbecomes an easy matter to lithograph 'thegrid as the grid combinationmay include a heavy perforated sheet which may be undecorated, unitedwith alight covering sheet which may be decorated. This advantageaccrues also when a plating is to be used as the plating may be providedon the cover sheet only. f

a tube; a metal member for Accordingly, further objects of my inventionare to provide a novel fabricated metal having a covered bend line; asmooth covering' affixed to the bending line; a form of bending lineadapted to retain a covering for the bend line; and a gridded bend lineto which imperviousness has been restored.

Other objects of my invention will be apparent in the detaileddescription following in connection with the drawings which form a partof these specifications, and in which:

Figure 1 is a perspective view of my novel metal construction applied toa shape suitable for reinforcing the front open end of a cabinet.

Figure 2 is a perspective view of -my novel metal construction appliedto a shape suitable for securing a closed end in a container.

Figure 3 is a perspective view of my novel metal construction applied toa shape suitable for connecting sheet material.

Figure 4 is an enlarged, fragmentary, perspective view of theconstruction shown in Figures 1, 2 and 3.

Figure 5 is a perspective view of a collapsible container showing theshapes of Figures l and 2 applied thereto.

Figure 6 is a fragmentary, perspective view showing two sheets ofmaterial joined by the shape shown in Figure 3.

Figure '1 is a cross section illustrating the shape into which theconstruction of Figure 1 may be formed.

Figure 8 is an enlarged, fragmentary, perspective view similar to Figure4, but with a covering partly broken oi applied thereto and securedthereby.

Figure 9 is similar to Figure 'I but illustrates the bend line shown inFigure 8.

Figure 10 shows the construction of Figure 8 when the sheet has beenbent over on both sides of the bend line in an enlarged, fragmentary,perspective view. y

Figure 11 shows a modified form of covering applied to the constructionof Figure 3.

Figure 12 is an enlarged, fragmentary. perspective, view of a. modifiedform of covering.

Figure 13 is an enlarged fragmentary, perspective, view of a modicationof my novel metal construction showing the method of applying thecovering of Figure 12.

Figure 14 is a cross section similar to Figure '1 but using the coveredconstruction shown in Figure 13.

.Figure 15 is an enlarged, fragmentary perspective view similar toFigure 4 showing a modied form of grid.

Figure 16 is an enlarged cross sectional view on the plane I6-I6 ofFigure 15.

Figure 17 is an enlarged cross sectional view on the plane |1-I1 ofFigure 15.

In Figure 1, I have illustrated the application of the principle to ametal reinforcing member which is used in connection with an improvedcasing having the general construction of the casing shown in myapplication Serial No. 693,841 filed October 16, 1933.

As shown, the member 20 is provided with a pluralty of securng prongs2l, formed by punching these prongs from the metal so that the prongsprotrude at right angles to the surface of the metal. Two pockets 22 and22 formed by slitting and embossing the metal are located at oppositeends of the member 20. Along one edge ofthe member 20 is the embossing23 for form- -carrying a roller 25.

ing a rabbet. upon which .is mounted a pin 24 Extending alon the member2U, Figure 1, are two rows of slots 6 and 21 shown in greater detail inFigure 4 as viewed from the sideopposite that shown in Figure l. Theslot 26 is formed by punching slits 26, 29'and 30, and -the slot 21 isformed by similar punched slits 28', 26' and 30'. Each of these threesets of slits is formed by punching the metal along three sides of arectangle, the same punching operation also bending the metal into anarcuate shape as shown at 3l and 3|. In the punching operation, none ofthe metal need be removed to form the slits and slots.

As will be evident, in such a member. there is a differential of theresistance to flexure along a line parallel with the row of slots 26 and21.

If therefore a force is applied to bend the metal longitudinally atright angles to the plane of the member of the Figure 1, the metal willhave less resistance to the bending along the lines of slits 26 and 21than at other longitudinal sections of the blank. It is thereforepossible to provide a predetermined shaping of the member 20, bent alongthesections 26 and 21 as illustrated in Figure '1.

It will be noted in Figure 4 that due to the.

bending out 'of the arcuate wings 3l and 3l' a series of openingsforming the slots 26 and 21 appear in the unbent blank. However, whenthe blank is bent into position as shown in Figure '1, these slotsl aresubstantially completely closed due to the metal of the member 20bending around the wings 3| and 3|' and coming into contact with theedgesof these wings.

As shown inFigure 4 there are a number of .nat straps I9. One of thesestraps is located between each pair if slots 26 and 21, ending at 29 andand an adjacent pair of'similar slots. These straps act to hold thesheet as a unitary struc-ture and also act to support the bent out wings3l and 3|'.

When the structure is produced from thin metal, I find that greaterrigidity of the unit may be obtained if in the punching operation theseconnecting straps are formed out of the plane of the sheet, as shown inFigures 15, 16 and 17, where the connecting straps I9 are formed into anarcuate shape by dies. I also find that by properly positioning the bentout portion of the straps so that the end I8 of the bent out portion ofthe strap i9 lies just inside of the edge 26 of the slot 26 and that theedge I8 of the bent out portion of the strap I9' lies just inside of theedge 28 of the slot 21, the bend line may be more accuratelypredetermined than where the connecting straps are at as shown in Figure4.

With such a metal suitably secured as by prongs 2| to a supporting basesuch as the walls of a casing, a force applied at right angles to theplane of the member will invariably bend it into an arc formed by thetwo rows of slots 26 and 21 due to the `diierential in the bendingresistance of the metal, as illustrated at 32 in Figure 7. Thus, as themetal is bent, it automatically assumes a predetermined curved shapewith the edges of the slitted metal and the edges of the main section inengagement with each other. v In Figure 2, I have shown a modificationsuitable for use as a means of holding in place the rear panel of acollapsible container, such as is shown in my copending applicationSerial No. 693,841. Figure 2 has the same form of bending line as hasFigure 1. The difference between the 'tion suitable for uniting twoportions of sheet material along a bending line. lAs shown member 34 isprovided with a plurality of securing prongs 2|, formed by punchingthese prongs from the metal so that the prongs protrude at right angles,as has been explained. Two rows of these prongs are shown, one at andthe other at 35'..

Lying between these two rows of prongs are two rows of slots 26 and 21as' shown in greater detail in Figure 4, which slots have been describedin4 detail.

In Figure 6, I have shown member 34 of Figure 3 applied to two pieces ofsheet material 36 and 36'. The member 34 is unltedlto sheet 36 by therow of prongs 35 and to sheet 36 by the row of prongs 35'. Each oftheprongs 2| are clinched over on the sheet material in the manner shown at31 in Figure 7, thereby firmly uniting the three members 34,-36 and 36',in a manner such that the rows of slots 26 and 21 form a manuallybendable joint at the junction of members36 and 36".

It is of course obvious that the fragmentary view of Figure 4 need notbe part of a relatively narrow strip of inetal such as is shown inFigures 1,. 2 and 3, but it may have a fragment of a relatively widesheet of metallic material havingone or more rows of pairs of slots 26and 21 which form predeterminedlines upon which the-sheet may be bentmanually. Such a sheet may be used for various construction purposes,either without a backing of non-metallic material ailxed thereto, or byitself as a metallic sheet.

In the examples so far described, the Joint produced at the bending linehas been one having the appearance of aregular line of grids, bothbefore or after, the member has been bent along the bending line; andwhile after bending, the slots are substantially closed they are notentirely so. Moreover, as has been explained for some uses aconsiderable compressive strength is required in the grid member.

I have found that, I may modify my novel construction in such a mannerthat additional compressive strength may be provided, a substantiallyimpervious sheet may be secured, and a smooth unbroken surface may beobtained over the bending'line. Besides having these structuraladvantages, the construction lends itself to various decorativepurposes.

In Figure 8, I have shown an enlarged, fragmentary, perspective viewsimilar to that shown in Figure 4. As in Figure 4 there are two rows ofslots 26 and 21 in the metal member 33. Each slot 26 is formed by slits28, 29, and 38, and each slot 21 is formed by slits 28', 29', and 38'.Each of these three sets of slits is formed by punching the metal alongthree sides of a rectangle. In the same punching operation the metal isbent into an arcuate shape inone direction as shown at 3| and 3| orinto-an arcuate shape in the other direction as shown at 31 and 31. Ihewings 3| and 3|' are for the same purpose as the wings shown in Figure4. The wings 31 and 31', however, also serve to mount the open box likechannel member 38, which is preferably of somewhat lighter metal thanthat of the member 39. 'I'he channel member 38 is firmly clinched overthe is shown as applied 38 but the grids formed by the punchings arecovered with a strip of metal securely fastened to the punched member,and lthis fastening is through the means of the punchings themselves, asis shown clearly in Figures 8, 9 and 10. It will be understood that themember 36 may be plain `polished metal, or it may be painted, enameled,-

lacquered, embossed, or otherwise nished as may be required to llt inwith the finish and design of the article of which the member 38 is toform a part.

While I have shown three sets of wings turned in the direction of thewings 3| and 3|' for each set of wings turned inthe direction of wings31 and 31', itis of course obvious that this ratio may be varied asdesired so long that each of the wings 31 and 31' are suiiiciently closeto a set of similar wings that the channel 38 receives adequate support.Moreover, it may be desirable in certain instances to turnall of thewings in the direction of wings 31 and 31'; and thus to make each set ofwings a supporting and securing means for the channel 38.

- In Figure 11, I have shown a modified method of covering the bendingline. In the ligure, I have shown a form similar to that shown in Figure3, and I cover not only the line of the grid like openings 26 and 21 butalso the openings left in the metal in the production of the prongs 2|.In the gure the metallic member 34, which is the same as that shown anddescribed in connection with Figure 3, is preferably covered with asheet of card beard 4|. 'I'his sheet 4| is of substantially the samewidth as member 34, and is retained -in place by the metallic covering42. This covering is preferably of somewhat thinner material than ismember 34. This member 42 has the facing 46, the two anges 43 and 43'and the two iange extensions 44 and 44'. The flanges and the flangeextensions t tightly around the members 34 and 4| and thus bind allthree pieces (34, 4| and 42) securely together. In addition to thisbinding action, adhesive may be used between the various surfaces, orthe various layers may be combined solely by adhesive means.

The purpose ofthe yielding member 4| interposed between the grid member34 and the cover member 42 is to prevent the shape of the grids 26 and21 and .the prong perforations `showing through the cover when themember is bent in themanner as has been described, as may occur when themember 42 is of thin metal. The purpose is also to prevent piercings ofunder-layer effecting thin over-layer from blow of the tool in attachingpress. When member 42 is not so thin that the grids the cover, even'ifyielding member 4| is omitted, this member 4| may be left out of thecombination; which will then consist of the grid member 34 and the covermember 42.

Where the yielding member is included, the crease or score lines 45 and45' may be provided in the member 4|. These score lines are superposedsubstantially upon the slot lines 26 and 21, and assist the slot lines26 and 21 in forming a predetermined bend line upon which the sheet maybe manually bent.

A further modification of my covered grid construction is shown inFigures 12, 13 and 14.

Figure 12 shows the grid cover from the rear view. This consists of thecover 41 in the general form of a channel, having the flanges 48 and 48'and the flange extensions 49 and 49. The flanges 49 and 49' are punchedso as to form sets of four lugs 50a, 50D, 50c, and 50d.

These outer edges of these lugs are spaced slightly from the face of theflanges 48 and 48' so that when the cover member 41 is placed over theholes 5i of the member 52, Figure 13 the holes 5I will be fully covered;In this modification the bending is controlled by the line ofrectangular holes 5I in the member 52.

The sets of lugs 50a, 50h,- 50c, and 50d are so spaced that when themember 41 is superposed upon member 52, each set of lugs will enter into'and fit closely within one of the series of holes 5i. After the coverlugs have been tted within the holes 5i they are clinched over as shownat 50a', 50h',- 50c' and 58d of Figures 13 and 14.

It will be further `understood that, while in the gures I have shown aset of four lugs for each of the openings 5|, it is not necessary that aset of lugs be provided for each of the openings 5|, and neither is itnecessary that four lugs be provided in any opening. Either the pairs oflugs 50a and 50d or the pairs of lugs 50h and 50c are sufficient to jointhe two members 41 and 52 and to properly position them relative to eachother. Furthermore, it is not even necessary that a pair of lugs beprovided for each opening that is fitted with a lug; but if only one lugis provided in a single opening, the lu s of different openings must bepositioned in diffeernt relative positions, as for instance, one openingbeing provided with a lug 50a and another opening with a lug 50d.

It will be further understood that I may use the type of grid with theopen holes as shown in Figure 13 with the type of grid cover shown inFigure 11. Thus the plate 52 with the opening 5i may be substituted inFigure 11 for the plate 34 with the two lines of slots 20 and 21.

It can readily be understood that while each type of covering that Ihave shown is described in connection with a particular embodiment of mymetallic bending structure, a covering of proper form may be applied toany of the bending structures.

I claim:

1. In combination; a rst strip of metallic material having apredetermined bend line along which said strip may be bent manually anda second strip of material in cooperative relation with said rst stripfor adding strength to said iirst strip at the relatively weakened bendline; lugs integral with and extending from said second strip; saidstrips being joined to each other by said lugs.

2. In combination; a rst.material having a line of three sided slits,the slits being juxtaposed in suiicientiy close relation so as to form astress resistance differential in adjacent sections to provide apredetermined bending line along which said material may be bentmanually, and a second material covering said line of slots joined tosaid rst blank material by means of integral conformations on saidsecond material cooperating with portions of 'said rst material.

3. In combination; a rst material having aline of slits, the slits beingjuxtaposed in sumciently close relation so as to form a stressresistance differential in adjacent sections to provide a predeterminedbending line along which said material may be bent manually, and ametallic covering i'or said line of slits, said covering being unitedwith said ilrst material by means of integral bent out portions of said-covering clamping over portions of said first material.

4. A bent sheet material having a line of three sided slits formedtherein, the slits being juxtaposed in sufiiciently close relation sothat the material within said slits, being originally deformed out ofthe plane of said material, forms a line of wings comprising the bentout material and a line of slots comprising the openings left in thematerial on bending out said wings, said line of slots forming a stressresistance differential in adjacent sections on either side of a bendtherebetween and extending along the lin'e of said bend, said wingsbeing united with said sheet material along a line parallel to said lineof slots.

5. A bent sheet material having a line of three sided slits formedtherein, the slits being juxtaposed in sumciently close relation so thatthe material within said slits, being originally deformed out of theplane o f said material, forms a line of wings comprising the bent outmaterial and a line of slots `comprising the openings left in thematerial on bending out said wings, said line of slots forming a stressresistance differential in adjacent sections on either side of a bendtherebetween and extending along the line of said bend, said Vwingsbeing united with said sheet material on a line parallel to said line ofslots and substantially filling said slots when said material is bent onsaid predetermined bending line.

6. A bent sheet material having a line of three sided slits formedtherein, the slits being juxtaposed in sufciently close relation so thatthe material within said slits, being originally deformed out of theplane of said material, forms aline of wings comprising the bent outmaterial and a line of slots comprising the openings left in thematerial on bending out said Wings, said line of slots forming a stressresistance differential in adjacent sections on either side of a bendtherebetween and extending along the line of said bend, said wings beingunited with said sheet material on a line parallel to said line of slotsand substantially filling said slots when said material is bent on saidpredetermined bending line.

7. lnqcombination; a bendable sheet of metallic material and a strip ofmaterial in cooperative 8. In combination; a bendable sheet of metallicmaterial having a line of three sided slits along the bendable portionthereof; and a metallic strip covering said line offslits and joined tosaid bendable sheet by means of integral conformations on said stripcooperating with portions of said bendable sheet;

9. In combination; a bendable sheet of metallic material having a lineof slits along the bendable portion thereof, and a metallic covering forsaid line of slits, said covering being united with said bendable sheetby means of integral bent out portions of said covering clampingr overportions of said bendable sheet.

PHILIP ZALKIND.

